1. Field
Embodiments of the present invention relate to a secondary battery.
2. Description of Related Art
In a secondary battery, large-capacity batteries, in which a number of battery cells are made into a battery pack, are used as the power source for motor driven devices such as hybrid electric vehicles. The secondary battery is generally manufactured by forming an electrode assembly by positioning a separator as an insulator between a positive electrode and a negative electrode, inserting an electrolyte into a case, and assembling a cap assembly having electrode terminals with the case by allowing the cap assembly to seal an opening of the case.
Meanwhile, when excess heat is generated due to over-charge conditions or electrolyte decomposition, an internal pressure of the secondary battery may increase, potentially resulting in fire or explosion. Accordingly, a secondary battery of improved safety is desired.